Reversible ink cartridge unit for ball point pens



W. GRUBE El'AL Filed May 29, 1956 IN VEN TORS 'VV/L HELM GHz/5E.

FR/EDR/cf/Orro GRI/BE.

ATTORNEY Feb. 2l, 1961 REVERSIBLE INK CARTRIDGE UNIT FOR BALL POINT PENS fom om REVERSIBLE INK CARTRIDGE UNIT FOR BALL POINT PENS Wilhelm Grube and Friedrich Otto Grube, Heidelberg- Rohrbach, Germany, assignors to Kaweco Badische Fuellfederfabrik Friedrich Grube, Wiesloch, Germany, a firm of Germany Filed May 29, 1956, Ser. No. 588,096

3 Claims. (Cl. 1Z0-42.1)

This invention relates to ball point pens and more particularly, to the ink holding reservoir of a ball point pen.

Although some of the better fountain pens are provided with means to alert the user thereof when the supply of ink contained therein is nearly exhausted, there is presently no way of alerting the user of a ball point pen that his ink supply is low. Accordingly, the users of such pens are prone to experience the inconvenience of abruptly running out of ink while using same.

It is therefore one of the primary objects of the present invention to provide a ball point pen having an auxiliary source of ink.

It is another important object of the present invention to provide an ink holding reservoir for a ball point pen which may be reversed when the ink contained in one end thereof is exhausted.

It is still afurther object of the present invention to provide a reversible reservoir for a ball point pen having a projectable and retractable pen nib.

It is yet another object of the present invention to provide a reservoir for a ball point pen which can accommodate at least two different inks.

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extend from the free ends of the ink holding members closing same off while the sleeve inserted ends of the said members remain open. Pen nib 40 is covered by a cap assembly 42, 56, 26 which will be described later. Air spaces 44 and 46 are formed between the open ends of the tubular ink holding members and partitioning wall Briey stated, the ink holding reservoir of the present invention comprises a tubular holding member and two writingunits, each unit having a writing end of the ball point type and an ink reservoir, the latter being removablyl inserted in the holding member and the units extending` in opposite directions from the tubular member.

A fuller understanding of the invention and the manner in which its objectives and advantages may be realized will become apparent from the following detailed description thereof taken in connection with the accompanying drawing wherein:

Fig. 1 is a sectional view of a ball point pen devised in accordance with the present invention;

Fig. 2 is an illustration of an embodiment of the reversible reservoir of the present invention; and

Fig. 3 is a part sectional View of the reversible reservoir shown in Fig. 2. Y

Referring now to the drawing and more particularly to Fig. 1 thereof, the ballpoint pen of the present invention, designated generally by numeral 10, consists of a removable pen casing 12 wherein reversible reservoir 14 is disposed. Casing 12 consists of an upper part 16 and a lower part 18 which are detachably held in threaded engagement at 20. A conventional pen clip 22 is affixed to the upper member 16. A tubular end-piece 24 having a plunger 26 slidably mounted therein is detachably atixed to the free end of member 16 by threading 28.

Reversible reservoir 14, disposed within casing 12, consists in this particular embodiment of the invention of tubular ink reservoir members 30 and 32 inserted into and held in axial alignment by sleeve or holding member 34. A partitioning wall 36 formed as an integral portion of sleeve 34 extends between tubular members 30 and 32 dividing the sleeve into two separate chambers. Pen nibs or writing ends 38, 40 of the ball point type 36. Conduits 48 and 50 formed in the partitioning wall 36 provide communication between the interior of casing 12 and air spaces 44 and 46 for reasons hereinafter explained.

A coil spring 54 normally acts to restrain nib 38 from passing through an opening 52 located at the writing end of the casing by restraining the entire reservoir from moving forward in the casing. However, by depressing plunger 26 the resistance of the spring is overcome and the entire reservoir is moved forward in the casing and nib 3S is projected through opening 52.

The mechanism for locking the nib in projected or retracted position is located in the upper portion of the casing and consists of a sheath 56 which surrounds a part of the reservoir 32 and which is aiiixed to and movable with plunger 26. The sheath 56 contains a sleeve 42 surrounding the pen nib 40 and axially abutting the reservoir`32. The elements 56, 42 and 32 form a protective cap assembly for the nib 40 of the spare writing unit. A resilient clamping or locking member 58 in the form of a tongue extends outwardly from sheath 56 in the direction of the casing wall and is located between immovable ring 60 and an axially movable ring 62 when the nib is in the projected position shown in Fig. 1. A restraining ring 64 limits the movement of movable ring 62.

Initially, when the nib is in retracted position, clamping member 58 extends into a clearance between sheath 56 and immovable ring 60 firmly frictionally engaging the inside of the latter. With the depression of the plunger, the entire reservoir and the sheath are moved forward in the casing. The clamping member 58 is thereby'freed from immovable ring 60 and snaps outwardly vtoward the casing wall. When the member 58 is freely extended between movable ring 62 and immovable ring 60, as shown in Fig. l, the pen nib is more or less locked in projected position.

With the further depression of the plunger, the sheath 56 is again moved toward the writing end of the pen and the member 58 is pressed inside the movable ring 62. On releasing the plunger, due to the action of the spring 54, the entire reservoir and the sheath together with movable ring 62 is retracted in the casing, the movable ring maintaining member 58 flattened against the sheath as it moves toward immovable ring 60. The attened resilient member finally passes under the immovable ring to lock the reservoir in retracted position. The protracting and retracting mechanism for the pen nib does not form part of the present invention. The invention rleates to a reversible reservoir which is suitable for most conventional pens and which does not depend on the particular retracting mechanism used.

The cap or sleeve 42 surrounding pen nib 40 protects the nib at all times from injury during movement in the casing as above described or otherwise, shielding the nib from contact with the plunger and/or associated parts.

When the ink supply in primary reservoir 30 is exhausted, the casing is opened by unscrewing the member 18 from the member 16 and the entire reservoir 14 is removed therefrom. The assembly 26, 42, 56 is removed from the pen nib 40 and placed on nib 38. The aggregate 14 formed by the writing units 30, 38 and 32, 40, by the holding member 34 and the cap 42 is then replaced in reversed position in the casing with nib 40 ready to be projected through opening 52. The disassembling of the pen, the reversal of the reservoir, and the reassembling of the pen take only a few seconds and once reassembled, the pen is again ready for use.

1 Conduits 4 8 and 50 place air spaces 44- and 46 in communication with the atmosphere to insure that the pasty masses of ink contained in the reservoirs will be moved by pressure differential toward the writing ends of the reservoirs as ink is withdrawn at the said writing ends thereby maintaining a steady ow oi ink to the nibs.

Itmay be seen that by virtue of the present invention a ball point pen has been provided having an auxiliary source of ink. Moreover, by reason of the present invention, a reservoir for a hall point pen has been pro.- vided which can accommodate at least two different types ogfiink.. For example, the inks utilized may vary in color or intensity. Furthermore, the user of a ball point pen which has been made in accordance with. the present invention will be alerted to the fact that his primary ink SupplyY is exhausted. although his pen will still be usable thereby sparing him inconvenience.

Although the invention has been described in detail with respect to one preferred embodiment thereof, it will b e understood by those skilled in the art, after reading this specitcation, that various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.

What is claimed as new and desired to be secured by Letters Patent is:

`1.y In a ball point pen, an oblong casing having an Open, end, a holding member within said casing and being slidable in the direction of the longitudinal axis of said casing, a rst writing unit having a Writing end extendible through said open end of said casing and having an ink reservoir removably attached to said holding member, and a second writing unit having a writing end and an ink reservoir removably attached to said holding memher and extending from said holding member in a directionwhich is opposite to the direction in which said first Writing unit extends from said holding member, said Casing including two axially immovably disconnectably interconnected parts, said holding member and said writing units forming an aggregate reversibly inserted in said casing and extending into both of said parts, said parts having internal shoulder means of smaller cross section than said ink reservoirs for limiting axial movement of said aggregate when said parts are connected.

2. In a ball point pen as defined in claim 1 and wherein a protective cap assembly is placed on the writing end of the second unit, said casing having two open ends, said writing end of said rst unit extending through one of said open ends, and said cap assembly having a part extending through the second of said open ends for attording manipulation of said cap assembly to move said aggregate within said casing for extending the writingend of therst writing unit through the respective open end of saidV casing.

3. in a ball point pen, an oblong casing having an open end, a sleeve member within said casing and being slidable in the direction of the longitudinal axis of said casing, a first writing unit having a writing end extendible through said open endof said casing and having an ink reservoir removably inserted in said sleeve member, a second writingunit having a writing end and an ink reservoir removably inserted in said sleeve member and extending from said sleeye memberV in a direction which is opposite to the direction in which said rst Writing unit extends from said sleeve member, said casing having two disconnectably connected parts, said sleeve member and said writing units forming an aggregate reversibly inserted in said casing and extending into both said parts, a transverse wall withinisaid sleeve member, said ink reservoirsy abutting against said transverse wall, and air conduits in saidl transverse wall and extending t0 the outside of s aid sleeve member for aiording flow of air into said sleeve member to replace ythe ink used up in said writing ends.

References Cited in the le of this patentv UNITED STATES PATENTS 1,107,641 Badini- Aug. 18, 1914 1,368,944 Kurose Feb. 15, 1921 2,500,439 Tursky Mar. 14, 1950 2,593,366 Thull Apr. 15, 1952 27,603,186 FischerV July 15, 1952 2,741,226 Dietrich et al. Apr. 10, 1956 FOREIGN PATENTS 629,240 Great Britain Sept. 15, 1949 978,585 France Nov. 29, 1950 823,860 Germany Dec. 6, 1951 286,888 Switzerland Mar. 2, 1953 

